How long after a storm before it is safe to swim near a storm drain?

Answers

The best advice is not to swim near a storm drain; swimming at least 100 yards out cuts your risk of catching a disease in half. And the rule of thumb for swimming after a storm is to wait 3 days so that bacteria levels return to normal levels. It’s also a good idea to stay away from “enclosed” beaches such as those in/near marinas where there is less water flow and potentially more bacteria buildup.

After an extremely significant rainfall event or near a runoff source such as a river, coastal waters can become contaminated for as long as a week, particularly if there is a constant source of runoff from an inland source. Many states will post beach contamination warnings as well as closure signs if there is a significant threat to swimmer’s health.